ummagawd

iTrader: (1)

Okay... so long story short... I've got in my car:

1 - pair of HIDs
1 - 500w amp
1 - 200w amp
2 - air compressors (not sure of the power specs... but these suckers SUCK juice big time)
1 - air valve solenoid controller
1 - DTS 5.1 surround sound processor
1 - carputer (computer has a 90w power supply)
1 - touchscreen LCD
1 - CDRW/DVD drive
1 - digital coax to toslink converter
1 - 4 port USB

all supported by an almost 2 year old yellow top optima battery

When i use my turn signals... you can hear my engine idle oscillate with the flashing turn signals...

I'm making a grounding kit for my trunk AND engine bay.... but besides that... would a capacitor help out any?

Anyone with experience on those "voltage stabilizers" (apexi, sun systems, ebay brands)

Alexusoftime

yea a cap with help out but ur better getting a higher output alternator try ohio they make really good one...if getting a cap get atless 3farads or higher

sluggo

A couple of big caps might help. The real problem is that the engine is being loaded down by the alternator, which means that your alternator is running at it's design limit at your idle speed. This is not necessarily bad, but it's at least an indication that you might be able to solve the problem more simply and effictively by changing to a higher-output alternator instead of adding caps.

Caps are good at storing charge and dumping it quickly, giving the system an instantaneous power capability higher than what it normally would have. The key word here is "instantaneous". This means that the caps will store charge and release it into the system as the voltage at their terminals starts to sag, but they cannot maintain power output continuously. Think of a cap as a battery with much lower capacity but much higher charge and discharge rates (fractions of a second). Once they start dumping charge, the voltage that they can maintain decreases and the system acts just like a system without caps. This is why caps are good for thumper stereos - the power demands of music are much, much, much higher during bass hits, and in between bass hits the caps have time to recharge.

Adding caps to a system that is continuously operating near it's current limit will not help at all. A higher output alternator, on the other hand, increases the continuous power capability of the system throughout the RPM range. For instance, unlike an audio amp, the air compressors require lots of current for more than a few seconds at a time. In order to maintain a constant 14.4 Volts at the power input terminals of the compressors, you need a power source (as opposed to power storage) that can supply steady current.

Caps may solve your engine loading problem, but I wouldn't bet the $100 or so it's going to cost to find out. It'd be great if you could borrow a friend's caps to test it out.

sluggo

ummagawd

iTrader: (1)

thanks guys... man i would be all for a highoutput alt... but i just replaced my alt a few months ago (before all these upgrades)

okay cool... what you guys have said makes sense and follows along the lines of what i've read about.

here's a weird thing i noticed... i temporarilly disconnected EVERYTHING... except for my 2 compressors... and electric fans (runs all the time)

and even if my compressors are NOT running... my engine idle oscillates with my turn signals still...

now i'm starting to doubt my electrical system in its stock state... what do you guys think? Think i got sold a bad alternator?

sluggo

The problem could be simply some faulty wiring in that one circuit. Try some other tests, now that you have everything disconnected - tap the brakes to turn on the brake lights, turn on the headlights, raise your seat all the way to the stops while you're sitting in it ... any of those should draw more current than a turn signal. If your idle RPM's don't drop when you do those things then you have a problem somewhere in your turn signal circuit. Possibly a short somewhere.

Also, since you say you just had a new alternator put in (the old one broke?), check and make SURE that the alternator belt is tight. Not guitar-string tight, but snug. If your belt is slipping at all you will have a very weak output from your alternator, sometimes not even enough to charge the battery.

sluggo

PS - Brain fart here. It's a serpentine belt. Duh. Oh well, check the belt anyway and see if there's anything obviously wrong at the alternator. Like maybe they used the wrong alternator or the wrong size of pulley on the alternator shaft.

ummagawd

iTrader: (1)

when my parking lights turn on the engine idle dips quite noticeably.... and the weird thing is when i turn the HID's on.. it doesn't affect the idle at all.

the brakes, windows (haven't tried the seat) affect the engine idle...

the serpentine belt should be tight.... but i have been having some annoying squealing issues and have had to use a good amount of belt dressing (i had to spray it like every time i started her up for a few days before the squealing went away) that was replaced a year ago... so i'm sure its still good.